Art of manufacturing billiard or pool balls.



. A. BURT.

Patented Dec. 20, 1910.

BPEOIIENB.

UNITED STATES PATEN T OFFICE.

ALONZO BURT, OF ALBANY, NEW YORK, ASSIGN OR OF ONE-HALF '10 VINCENT B.HUBBELL, OF NEW YORK, N. Y.

ART OF MANUFACTURING BILLIARD OR POOL BALLS.

Patented Dec. 20,1910.

Serial No. 514,806. (Specimens) To all whom it may concern:

Be it known that I, ALoNzo BURT, a citizen of the United States,residing at Albany, county of Albany, and State of New York, have made anew and useful Invention in the Art of Manufacturing Billiard or PoolBalls, of which the following is a specificatron.

My invention is directed particularly to a novel method or process offorming or making composition billiard or pool balls of the pressedtype, such balls being made usually of compositions of celluloid andother substances and in well known public use.

My invention has for its objectsfirst, to provide a composition orpressed billiard or pool hall which shall perfectly polished or finishedsurface, and of'such a nature that it may be readily cleaned, and whencleaned will assume substantially the polished appearance or conditionof the ball when it leaves the factory; second, to provide a ball ofthis nature which shall very closely resemble wellknown ivory billiardor pool balls; third, to provide a ball of this nature in which thesurface thereof is of variegated colors, painted or otherwise coatedwith various marks or characters, and which characters or colors shallbe located under the surface of a transparent outer coating or shellattached to the surface of the ball proper; fourth, to provide a ball ofthis nature in which the parts of such ball shall be located beneath atransparent surface; fifth, to provide a ball of this nature having ahard elastic practically indestructible surface which will not abrade orpermit of the adhesion of fine grit or dust thereon.

In the manufacture of composition bilhard or pool halls, such as are inwell known public use, it has heretofore been customary to construct thesame by compressing the material, such as celluloid, bone-dust, etc,into the proper form or shape, through the agency of hydraulic pressure,such balls being either solid white or made in sections of variegatedcolors with the numbers and number rings painted thereon. Or, suchnumbers and number rings have been com- I structed of individual partssunken into the face of the ball. All such balls, however, when finallyprepared for the market, after being molded, are turned down to properspherical form, then glossed and waxed, un-

glossy or shiny by constant use,

have at all times a.

- and der which conditions they have the general appearance of ivoryballs. It is well understood, however, by those skilled in the art thatwhen they are used they lose their gloss and the surfaces thereofreadily receive and absorb small particles of dust or grit which cannotbe wiped ofl", but as a matter of fact become embedded therein thusgreatly depreciating the perfect balance or equilibrium of the sphericalmass thereof.

The present invention contemplates a decided improvement to the extentthat I incase such balls, as heretofore constructed, with aneXt-eriorspherical shell or coatin of a material which possesses the quality 0resisting abrasive effect due to grit, dirt or the like, and this shellis of such a nature.

that it constitutes, when secured in place in the manner hereinafterdescribed, a part of the ball proper, said shellbeing preferablytransparent and of such dense material that it will retain at all timesan exceedingly glossy or reflecting appearance.

For a full and clear understanding of my invention, such as will enableothers skilled in the art to which it relates to practice my novelmethod or process and to manufacture or construct my novel billiard orpool ball, reference is had to the accompanying drawings in which all ofthe figures are'upon an enlarged scale, Figure 1 being an elevation, andpart broken sectional view of a complete ball, and Fig. 2 a fullsectional view taken through a cat spherical circle of the ballillustrated 1n Fig. 1f. Fig. 3 is a part side elevational, partsectional view illustrating the manner of proceeding in the preliminarysteps of practicing my improved process, and Fig. 4 is a sectional viewillustrating the relation of the parts shown in Fig. 3 after they haveall been assembled preparatory toapplying the pressure which makes thecomplete ball shown in Figs. 1 and 2.

Referring now to the drawings in detail in all of which like letters ofreference represent like parts wherever used, A, B and C represent theparts of a completed or pressed ball, indicated as a whole by the letterE. The polar sectors A and B are say white and the equatorial sector Cred, with the number and number-ring either painted thereon or sunkeninto the body of the equatorial sector in a manner well understood byetc., to hydraulic pressure by inclosing each one of them within twohemispherical soft rubber on s F F, Fig. 3, havin each the contour oslightly more than ha f the ball, the equatorial edges of these cupswhen in position on. the ball slightly overlapping. After these on s aresecured in position around the ba by rubber cement, it is then immersedin' a liquid, as water, contained in what is known in the art as theHyatt hydrostatic gum and subjected to such temperatures and additionalpressures that the ball when completed has received the necessarypressure to make it a perfectly pressed spherical ball. In the practiceof such method, however, it sometimes happens that the liquid isadmitted between the joints of such cups, thereby deforming the surfaceof the ball. To overcome this serious trouble, therefore, Ihave soconstructed these cups F, as illustrated in Fig. 3, that they aresomewhat deeper than as before constructed and have gradually taperedthe edges thereof, as shown, so that perfectly air and water-tight edgesare jobtained which may be accurately cemented or sealed. as will bereadily appreciated on examina tion of Fig. 4 of the drawings.

In the practice of my improved rocess I prepare, with shouldered male anfemale dies in a manner well understood by those skilled in the use ofdies, 2. pair of hemispherical cups-D I) (see Fig. 3) of puretransparent dense or hard celluloid, the same having each an outwardlyturned rim or flange G, shown'as very much exaggerated in Figs. 3 and4;, which rims are constructed by shoulders on the male and female partsof the dies as will be apparent. After the cups are thus formedfrom-circular disks of celluloid and placed in the manner described and.as shown in Fig. 3; completely encompassing or surrounding the ball E,the two soft rubber cups F are then successively drawn in oppositedirections over the ball and parts shown in Fig. 8, so that all of saidparts assume the relation shown in Fig. 4.

It is important in the construction of the hemispherical cups D and inthe construction of the ball proper that'the' interior spherical contourof each of the cups shall be mathematically the same as the likeexterior hemispherical contours of the ball which they are to cover, forthe reason that absolutely no air should be allowed to reractice to sub;ect plastic masses of cellu oid, bone dust,

4 pressures ranging main between the inner surfaces of the cups and theouter surface of the ball. I have ascertained that if air is permittedto remain therein an imperfect exterior surface of the shell results andit assumes, under high pressure, a honey-comb appearance. After the cupsF are drawn over the assembled parts inthe manner shown in Fig. 4 thetapered edges are secured together .With rubber cement in such manner asto assure a perfectly air and water-tight joint, it being obvious thatin the construction of a ball the united flanges G should have a minimumarea, and it also being apparent that any imperfections in the ballwould occur at this equatorial diameter, where the mass of materialwould naturally be greater, so that it could, after the bail is pressed,be turned down in a lathe. The parts surroundin the ball as thusassembled are now subjected to an enormous liquid pressure ilr a Hyatthydrostatic gun, which pressure causes the two cups to be united to theouter surface of the, ball E at every point so that when subjected tosufiicient pressure? said ball assumes the form illustrated in Figs. 1and 2. I have had mostexcellent results in thus constructing my improvedbilliard or pool ball in :1 Hyatt hydrostatic gun with from 2000 to 2300pounds per square inch; I prefer, however. to use the maximum pressureof 2300 pounds. The outer casing D is a thin transparent coating which,when polished in the usual way. has for ordinary use an indestructible.glossy appearance and resists any tendency to permit of the attachmentof dust, grit or any substance of like nature, such transparent coatingalso effectually protecting the number or numbers on the outer face ofthe ball and also giving to the ball a greatly improved elastic effect.

In the practice of my improved process of manufacturing billiard or poolballs, as hereinbefore described, I have obtained remarkable results inthe use of well known forms of composition balls in which celluloidconstitutes the binding agent of the ball proper, and in the use ofcelluloid shells or cups in the manner described, it being important, asI have ascertained, that the shell, to be secured to the ball proper,should have substantially the same coeliicient of expansion as the ball,it being obvious that should the shell have a less coeiiicient ofexpansion than the ball such shell would readily crack or break; on theother hand, should the shell have a greater co efiicient of expansionthere would be a tendency to Wrinkle or materially disturb the balancedcondition of the'completed ball.

I am aware that it has heretofore been proposed to form golf balls bycompressing together two difierent materials of difierent density, oneof said materials being rubber,

efficient of expansion, the outer coating of the ball, when securedunder such pressures as hereinbefore referred to, being effectuallyunited to every part of the surface of the ball proper, so that everypart of'the ball having such casing is of substantially equal density.

I make no claim hereinafter to the novel form of ball which results fromthe process herein claimed, as this feature constitutes the subjectmatter of a divisional application filed by me in the United StatesPatent Oflice on the 7th day of February, 1910, bearing Serial No.542,442.

Having thus described my invention what I claim and desire to secure byLetters Patent of the United States is 1. The described process ofproviding a composition billiard or pool ball with a nonabrasivesurface, consisting in compressing, at a minimum pressure of about 2000pounds per square inch, a relatively thin coating or shell of celluloidaround a basic ball having celluloid as one of its elements, and insimultaneously applying sufiicient heat thereto until said coating andthe ball are united at all points.

2. The described process of providing a composition billiard or poolball with an outer surface which shall not abrade or tarnish in use,consisting in covering or surrounding such ball with a plurality ofcurvilinear cups constructed of a substance having substantially thesame coefficient of expansion as the material of which the ball iscomposed; then subjecting the same to a minimum pressure approximating2000 pounds per square inch, and simultaneously applying heat until suchcups and the ball are united at all points.

3. The described process of providing a composition billiard or poolball-With an outer surface which shall not abrade or tarnish in use,consisting in covering or surrounding such ball with a plurality ofcurvi linear cups constructed of a substance having substantially thesame coefficient of expansion as the material of which the ball .iscomposed; then subjecting the same to a minimum pressure approximating2000 pounds per square inch, and simultaneously applying heat until suchcups and the ball are united at all points, and finally in turning ortruing the ball at those points where the cups are united.

4. As an article of manufacture a compressible hemispherical shaped cupof celluloid adapted to fit with exact accuracy upon or about thesurface of a ball to which it is to be attached, saidcup having anoutwardly turned rim or flange at its equatorial edge.

5. Means for use in compressing billiard or pool balls embracing aplurality of flexible cups having each a prolonged tapering edge andadapted together to overlap the ball when in place therearound.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

- ALONZO BURT.

Witnesses H p C. J. KI TNER, MARGEL MULE'r.

